1. Field of the Invention
The present invention pertains to a scroll-type expander-compressor drive system having a scroll-type expander which is used to drive a scroll-type compressor or pump. The scroll-type expander driven compressor system is particularly adaptable for use in combination with a combustor, such as an internal combustion engine, which produces exhaust gases for driving the scroll-type expander. The scroll-type expander may then drive the scroll-type compressor which can be used to supply pressurized air to the combustor or to drive other systems.
2. Description of the Prior Art
The use of a scroll-type expander driven compressor assembly in combination with a combustor is known in the art as exemplified by the teachings in U.S. Pat. No. 4,192,152. In such known arrangements, the exhaust gas from a combustor is used to drive an expander which is mounted upon a common shaft with a compressor. By this arrangement, the exhaust gas from the combustor drives the expander which, in turn, drives the compressor in order to provide pressurized air for the combustion process.
Such known expander-compressor drive systems have been found to be extremely efficient due to the inherent operating nature of scroll fluid devices. Unfortunately, the advantages of such drive arrangements have not heretobefore been fully realized due to various deficiencies associated with the prior art systems. For instance, such prior art systems have been rather bulky due to the manner in which the expander drives the compressor, the use of individual counterweights for the scrolls and the inclusion of separate synchronizers between the drive and driven scroll elements. In addition, when used in combination with a combustor, the scroll fluid devices are subject to a wide range of temperatures which tend to expand or contract the relatively rotating scroll elements which results in system vibrations, noise and efficiency losses.
Therefore, there exists a need in the art for a scroll-type expander driven compressor assembly which is compact, compensates for thermal expansion and contraction and which is simple in construction such that it can be readily manufactured with a minimum number of parts while being capable of a long service life.